The present invention relates to a mount member by which components of an optical apparatus are attached to or detached from each other.
Generally with optical apparatus including an interchangeable part, typically in the case of cameras in which an interchangeable lens is used, the interchangeable lens and the camera body are adapted to be brought into intimate pressing contact with each other by a great force at the mount surfaces of their mount members when the lens is attached to the camera body so that the focal plane of the lens coincides with the plane of the film in the camera. Accordingly when the interchangeable lens is attached to or detached from the camera body, the mount surfaces are caused to slide on each other under great pressure. The mount surface of such a mount member is formed by plating nickel-chrome on a stainless steel or brass substrate or by subjecting an aluminum substrate to anodic oxidation and therefore has a very high coefficient of friction.
To reduce the friction between the opposed mount surfaces, a lubricant is usually applied to the mount surfaces. However, this involves the drawback that when the interchangeable lens is detached from the camera body, the lubricant coating (or film) is easily removable by contact with some other article or by being erroneously wiped off by the user upon cleaning of the camera. When the mount surface is thus depleted of the lubricant, the lens fails to smoothly fit in and disengage from the camera body due to increased friction between the mount surfaces, producing wear on the mount surfaces. Such wear, if produced markedly, is likely to result in the serious objection that the flange back of the camera alters.
The above problems experienced with cameras are also encountered with various other optical systems generally used.